Method and apparatus for making metallic corrugated walls



1936. F. K. BEZZENBERGER 3 METHOD AND APPARATUS FOR MAKING METALLIC CORRUGATED WALLS Filed Aug. 1, 1925 INVENTOR. MZ/f 5655622 Zmyar BY I =4 Y ATTORNEYS for producing such articles.

Patented Aug. 25, 1936 METHOD AND APPARATUS FOR MAKING METALLIC CORRUGATED wALLs- Fred K. Bezzenberger, Cleveland Heights, Ohio,

assignor, by mesne assignments, to The Fulton Sylphon Company, Knoxville, Tenn., a corporation of Delaware Application August 1, 1923, Serial- No. 655,136

27 Claims. (Cl. 15373) The present invention, relating as indicated, to a method of and apparatus for making metallic corrugated walls, is more particularly directed to a new and improved method of making so-called metal bellows, which are now widely used in valves and thermostatic devices and other devices of various types, and to an improved apparatus To the accomplishment of the foregoing and related ends, said invention, then, consists of the means hereinafter fully described and particularly pointed out in the claims.

The annexed drawing and the following description set forth in detail certain means and one mode illustrating, however, but one of various ways in which the principle of the invention may be used.

In said annexed drawing:-

Figure 1 is a section on the line l-l, Fig. 2, showing the construction of dies with which the present method may be carried out; Fig. 2 is a vertical central section on the line 2-2, Fig. 1; Fig. 3 is a partial vertical section on the same plane as that of Fig. 2, but showing the dies in a difierent relative position; and Fig. 4 is a view in perspective of one of the controlling cams used for operating the dies.

Flexible corrugated walls or bellows are now commonly made by first drawing or otherwise forming a relatively long tube, which is then rolled to produce inwardly and outwardly extending corrugations from the original cylindrical wall of the tube. In this method of producing bellows a number of rolling operations are necessary, with one or more annealings of the partially formed bellows between certain of the rolling operations. Annealing is desirable because during the deformation of the metal in the rolling operations, the metal becomes very much hardened and should be softened by annealing before the subsequent rolling operations. The present method is designed to avoid the large number of operations necessary in'the rolling of the bellows, and to also provide a very much superior quality of metal throughout the entire bellows than is possible to secure by the present method, and at a very much less cost.

In Fig. 2, I have shown one form of apparatus which may be used to carry out the present method, and which consists of a frame 1, consisting of a plate 2 and a cylindrical flange 3, the plate 2 being provided with an opening 4 therein, in which a tube 5, which is to be corrugated, is mounted. Cooperating with the fiange 3 is a platform or support 6 mounted on suitable means, such as springs I, so that it may be moved with respect to the upper plate 2 of the framework. for the purpose which will be explained presently. The tube 5 is first introduced through the opening 4 and seated against the lower platform or support 6 after which a plunger 8 is introduced 5 into the upper end of the tube and presses that end of the tube firmly betweenit and the wall of the opening 4, which is slightly'tapered to firmly seal this end of the tube between the plunger and the plate. The plunger is provided withan open- 10 ing 9 therethrough for the introduction of fluid pressure into the interior of the'tube for expanding the same .into engagement with the forming I means, which will now be described.

Extending through the interior of the frame- 15 work I are two square shafts lfl an'd II which are journaled at their lower ends in suitable flanged bushings l2 set into the platform or support 6.

in Fig. 2, and in the initial position of the appa- '25' ratus the half rings are equidistantly spaced,.as shown in Fig. 2, andare in approximate contact with the wall of the tube 4 when the latter is first inserted in the apparatus.

Slidably, but non-rotatably, mounted on the 30 shafts l0 and H are a series of cams l5, one of which is shown in perspective in Fig. 4, each cam being provided with one portion It extending a considerably greater distance from its axis on the shaft II) or H than the other portion l1, and the 35 cam having beveled surfaces It and IQ for cooperation and contact with correspondingly beveled surfaces 2|] and 2| on each of the forming dies or half rings l3. The enclosing frame I, as

well as the dies I3, is formed in two parts, as 40 indicated in Fig. 1, the two parts being held together in any suitable way as by blocks 22 and bolts 23, whileall of the dies are slidably mounted on rods 24, which extend from the upper plate 2 into and through the lower platform 6. the bellows has been formed the halves of the frame, platform and diescan be detached one from the other to permit of the convenient removal of the bellows upon the lifting of the plunger 8 from its engagement with the interior upper wall of the tube.

The present method consists, briefly stated, in first mounting a tube between equidistantly spaced dies, then introducing fluid pressure into the interior of the tube to expand the wallsof the After 45' same info contact with the dies and desirably slightly bulging the same about the points of contact between the wall and the dies, and than allowing the dies and the tube to collapse axially of the tube during the further expansion of the walls of the tube into a close engagement with the corresponding walls or surfaces of the dies as the latter are allowed to move toward each other to compensate for the decreasing length of the tube as the wall of the same is expanded into the desired corrugations. In the present apparatus the tube is first mounted as already described, the dies l3 being in the position shown in Fig. 2, with their radial outer surfaces 20 and 2| between the surfaces on the long side of the cams l5, as shown in Figs. 1 and 2. Fluid pressure is then introduced into the interior of the bellows through the passage 9 and the plunger 8 to a sufficient extent to expand the wall of the tube as indicated by the dotted lines 25 in Fig. 2, between the points of contact of the wall of the tube with the inner edges of the dies. As soon as this expansion of the tube has taken place the shafts l and II are simultaneously rotated to turn the cams 15 through 180 degrees, bringing the short portions of the cams between the dies, and allowing the dies to progressively and evenly move toward each other, while at the same time the fluid pressure is maintained or increased to still further expand the wall of the tube into a complete and full engagement with the forming inner surfaces of the dies, which dies in their final position are in lateral contact as is shownin Fig. 3. which forms the complete'corrugations in the tube. The dies are simultaneously and automatically moved axially of the tube to compensate for the decreasing length of the tube during the final expansion of its wall by means of the springs 1 which constantly press the platform 6 upward as fast as the turning of the cams l will permit of the axial movement of the cams and dies. Any suitable connections may be employed to correlate the movement of the two cam shafts l0 and H and the increasing of the fluid pressure through the passage 9 into the interior of the tube, and I have not thought it necessary to show such connections. At the close of the operation just described the fluid pressure is released from the interior of the tube, and the halves of the frame. dies and supporting platform are discon nected from each other and opened or detached to permit of the removal of the bellows and the mounting of the fresh tube in position. The entire operation is very much simpler and quicker than the rolling methods now commonly employed, and is therefore very much less expensive, while it also produces a superior article to that now made.

Other forms may be employed embodying the features of my invention instead of the one here explained. change being made in the form or construction, provided the elements stated by any of the following claims or the equivalent of such stated elements be employed, whether produced by my preferred method or by others embodying steps equivalent to those stated in the following claims.

I therefore particularly point out and distinctly claim as my invention:-

1. In a method of making flexible corrugated metallic bellows, the steps which consist in mounting a tubular metal element within a series of spaced parallel rings, applying fluid-pressure within said element to partially expand the same between said rings without exerting a force axially sufficient to collapse said element, and thereafter allowing said rings to float to permit of longitudinal contraction of said element while applying the fluid-pressure to still further expand said element between said rings.

2. In a method of making flexible corrugated metallic bellows, the steps which consist in mounting a tubular metal element within a series of spaced parallel rings, applying fluid-pressure within said element to bulge the same between said rings, and then releasing said rings to permit of longitudinal contraction of said element while continuously applying the fluid-pressure to still further expand said element between said rings.

3. In a method of making flexible corrugated metallic bellows, the steps which consist in mounting a tubular metal element within a series of spaced parallel rings, applying fluid-pressure within said element to bulge the same between said rings, and then releasing said rings to per.- mit of progressive longitudinal contraction of said element'while simultaneously intensifying the fluid-pressure to still further expand said element between said rings.

4. In apparatus of the character described, the combination of a frame having an opening therein, a series of rings mounted in spaced parallel relation within said frame, means for supplying fluid .pressure to the interior of a tubular element mounted in said opening and within said rings to expand the wall of said element into interlocking contact with said rings, bevelled cams interposed between said rings, and means adapted to move said cams to vary the spacing between said rings.

5. In a method of making flexible corrugated metallic bellows, the steps which consist in initially inducing a deforming pressure within a tubular element mounted within spaced parallel rings without exerting a force axially sufficient to collapse said element, and thereafter progressively and uniformly releasing said rings while increasing said pressure to force the wall of said element into corrugations between said rings.

6. In a method of making flexible corrugated metallic bellows, the steps which include positioning a tubular wall in operative relation to spaced parallel die rings, subjecting said tubular wall to a fluid under pressure to lock said rings to said tube, and then forming corrugations in said tubular wall by increasing said fiuid pressure and simultaneously releasing said rings to permit the relative approach thereof.

7. In a method of making flexible corrugated metallic bellows, the steps which include positioning a tubular wall in operative relation to spaced parallel die rings, subjecting said tubular wall initially to a deforming pressure to bulge said wall with respect to said die rings, and then increasing said fluid pressure and simultaneously releasing said rings to permit the relative approach thereof.

8. In a method of making flexible corrugated metallic bellows, the steps which include positioning a tubular wall in operative relation to spaced parallel die rings, subjecting said tubular wall to fluid pressure to lock said rings to said tube, and then forming corrugations in said tubular wall by increasing said fiuid pressure and simultaneously releasing said rings to permit the rela tive approach of said die rings while exerting a pressure axially of said tubular wall.

9. In an apparatus of the character described, the combination of a series of rings mounted in spaced parallel relation, means for supplying fiuid pressure to the interior of a tubular wall within said rings to bulge said wall between said rings, and releasing elements interposed between said rings and movable to release said rings and permit said rings to move relatively toward each other under the deforming action of said fluid pressure on said wall.

10. In an apparatus of the character described, the combination of a series of rings mounted in spaced parallel relation, means for supplying fluid pressure to the interior of a tubular wall within said rings to bulge said wall between said rings, releasing elements interposed between said rings and movable to permit said rings to move relatively toward each other under the deforming action of said fluid pressure on said wall, and means automatically following the decrease in overall length of said wall and-maintaining an axial pressure on said wall.

11. In an apparatus of the character described, the combination of a series of rings mounted in spaced parallel relation, means for supplying fluid pressure to the interior of a tubular wall within said rings to expand said wall, movable elements interposed between said rings and movable to permit said rings to move relatively toward each other under the deforming action of said fluid pressure on said wall, and resiliently operated means for maintaining an axial pressure on said wall as said wall decreases in overall length.

12. In an apparatus of the character described, the combination of a series of rings mounted in spaced parallel relation, means for supplying fluid pressure to the interior of a tubular wall within said. rings to bulge said wall between said rings, beveled cams interposed between said rings, means adapted to move said cams to vary the spacing between said rings, and means for maintaining an axial pressure on said wall as said wall decreases in overall length.

13. In a method of making flexible corrugated tubular walls, the steps which consist in mount ing a tubular metal element within a series of spaced parallel rings, applying fluid pressure within said element to partially expand the same between said rings without exerting a force axially sufflcient to collapse said element, and thereafter allowing said rings to float to permit of longitudinal contraction of said element while continuously applying the fluid pressure to still further expand said element between said rings.

14. In a method of making flexible corrugated tubular walls, the steps which consist in mounting a tubular metal element within a series of spaced parallel rings, applying fluid pressure within said element to partially expand the same between said rings without exerting a force axially sufficient to collapse said element, and thereafter allowing said rings to float to permit of longitudinal contraction of said element while continuously applying the fluid pressure to still further expand said element between said rings, and also exerting a pressure axially 01 said tubular wall which is less than that necessary to deform said wall.

15. In a method of making flexible corrugated tubular walls, the steps which consist in mounting a tubular metal element within a series-of spaced parallel rings, applying fluid pressure within said element to expand the same into bulges between said rings, and then releasing said rings to permit of longitudinal contraction sfill further expand said element between said 1 use.

16. In a method oi making flexible corrugated metallic bellows, the steps which consist in mounting a tubular metal element within a series of spaced parallel rings, applying fluid pressure within said element to bulge the same between said rings without exerting a force axially sufilcicnt to collapse said element, and thereafter allowing said rings to float to permit of longitudinal contraction of said element while continuously applying the fluid pressure to said element and applying an exterior force axially of said element to expand said element into corrugated form between said rings.

17. A method of making a thin wall, corru-' gated, tubular element, which comprises positioning a tubular blank between heads, one of which heads is provided with an opening communicating with the interior of the assembly, supporting the assembly with a series of rings spaced at uniform intervals through the length of the assembly, and designed to prevent expansion of the tube at points of support, supplying fluid under pressure through the opening in the head for producing a preliminary bulging .of the wall of the tube, and thereafter'releasing said rings and subjecting the assembly to an endwisc pressure to contract the tube in length, while maintaining the internal fluid pressure through the opening in the head sufficient to sustain the walls of the tube during the contracting operation.

18. A method of making a corrugated metallic bellows, which consists in sealing the ends of a tubular member except for the provision of a restricted liquid opening through one end, connecting a source of fluid supply to the opening, providing the exterior of the tube with a series of encircling supports spaced lengthwise of the tube, exerting an internal fluid pressure to lock the wall of the tube to said encircling supports and thereafter subjecting the tube to an endwise contracting pressure while releasing said supports to permit freedom of movement of the supports lengthwise of the tube.

19. The method of making a corrugated metallic bellows, which consists in sealing the ends of a tubular member except for a restricted opening through one end, connecting the opening with a source of fluid pressure, assembling about the tube a series of supports each having an opening corresponding to the outer diameter of the tube, maintaining said supports in alignment, subjecting the tube to an internal fluid pressure to bulge the walls of the tube between the supports, and subjecting the tube to an endwise contracting pressure while releasing said supports to permit movement'thereof lengthwise of the tube in alignment therewith and maintaining the internal fluid pressure during the contracting movement.

20. The method of making a corrugated tubu= lar member adapted for use in thermostats and the like, which consists in sealing the ends of a tubular member except for a restricted opening through one end, connecting the opening with a source of liquid pressure, assembling a series of divisible plates lengthwise of the tube, each of the plates having an opening corresponding to the exterior diameter of the tube, maintaining the plates in alignment with the axis of the tube, subjecting the tube to an internal liquid pressure to bulge the walls of the tube between the plates, and thereafter releasing said plates and subjecting the tube to an endwise contracting pressure while permitting the plates to move lengthwise oi the tube and while maintaining the internal liquid pressure.

21. In a method of making flexible, corrugated metallic bellows, the steps which consist in mounting a tubular metal element within a series of spaced parallel rings, holding said rings in spaced relation and applying fluid pressure within said element to lock the same with said rings and then progressively releasing said rings to permit a longitudinal contraction of said element while continuously applying the fluid pressure to still further expand said element between said rings.

22. In the method of making flexible, corrugated metallic bellows, the steps which consist in mounting a tubular metal element within a series of spaced parallel rings, holding said rings in spaced relation and applying fluid pressure within said element to bulge the same between said rings, and then progressively withdrawing said holding means to allow said rings to move to permit a longitudinal contraction of said elements while continuously applying the fluid pressure and an exterior axial pressure to still further expand said element between said rings.

23. In a method of making flexible corrugated metallic bellows, the steps which consist in mounting a tubular metal element within a series of spaced parallel rings, holding the rings in spaced relation and applying fluid pressure within said element to expand the same between said rings and form a series of bulges, and then pro gressively withdrawing said holding means to allow said rings to move to permit a longitudinal contraction of said element while continuously applying the fluid pressure to still further expand said element between said rings.

24. In a method of making flexible corrugated metallic bellows, the steps which consist in mounting a tubular metal element within a series of spaced parallel rings, holding said rings in spaced relation and applying fluid pressure within said element to expand the same between said rings and form a series of bulges, and then releasing said holding means and allowing said rings to move to permit a longitudinal contraction of said elements while continuously applying the fluid pressure and an exterior axial pressure to still further expand the said element between said rings. e-

25. In a method of making flexible corrugated metallic bellows, the steps which include positioning a tubular wall in operative relation to spaced parallel die rings, holding said rings in spaced relation and subjecting said tubular wall to fluid-pressure to bulge the same between said rings, and then forming corrugations in said tubular wall by releasing said holding means and simultaneously permitting the relative approach of said die rings while continuously applying the fluid pressure to still further expand said wall between said rings.

26. In a method of making flexible corrugated metallic bellows, the steps which include positioning a tubular wall in operative relation to spaced parallel die rings, subjecting said tubular Wall to a fluid under pressure to bulge said wall between said rings while rigidly holding said rings stationary, and then forming corrugations in said tubular wall by releasing said holding means to permit the relative approach of said rings while simultaneously applying said fluid pressure to expand said wall between said rings.

2'7. In a method of making flexible corrugated metallic bellows, the steps which include positioning a tubular wall in operative relation to spaced parallel die rings, subjecting said tubular wall initially to a deforming fluid pressure to bulge said wall with respect to said die rings while rigidly holding said rings stationary, and then releasing said holding means to permit the relative approach of said rings while simultaneously applying said fluid pressure and an end pressure to expand said wall between said rings.

FRED K. BEZZENBERGER. 

